Waste water treatment method

Abstract

A waste water treatment method for treating waste waters containing a surface active agent comprising a condensate obtained by condensing, with formaldehyde, a sulfonated organic compound such as an aromatic compound, a fused benzene ring compound or a hetero compound, in which a flocculation treatment is combined with an active carbon treatment.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 
     
       1. A process for treating waste water containing from 1 to 1000 ppm of water-soluble salts of condensates obtained by condensing, with formaldehyde, sulfonates of mono or fused polycyclic benzenoid aromatic hydrocarbons having from 1 to 12 benzene rings, which comprises the sequence of steps of: (1) adding to said waste water from 50 to 1000 ppm of at least one inorganic flocculating agent while maintaining the pH of the waste water at from about 6.5 to about 8.5 to form flocs containing a portion of said condensates and removing the resulting flocs from the waste water, and then (2) adding to the treated waste water product from step (1) from 50 to 400 ppm of activated carbon and agitating same therein for a period of time effective to absorb the condensate into the activated carbon and then filtering the activated carbon from the waste water. 
     
     
       2. A process as claimed in claim 1 in which in step (1) there is also added to the waste water from 1 to 10 ppm of a polymeric flocculating agent. 
     
     
       3. A process as claimed in claim 1 in which the condensate is a condensate of sodium naphthalene sulfonate.